I need to make a hole near the corner of a kitchen worktop to bring up a
12v
power cable (with right-angled concentric plug) and aerial lead for
SWMBO's
new 6" LCD TV (so she can watch TV while preparing the dinner - yes, I
know!). Making a hole is a last resort,

Put an aerial amplifier feeding a length of wire under the surface and then
a simple loop aerial on the TV. Should work well enough for an LCD jobby.